Proportioning apparatus



Oct. 17, 1967 w. HAMILTON 3,347,416

PROPORTIONING APPARATUS Filed July 7, 1965 3 Sheets-Sheet l a l IllllINVENTOR WALL ACE HAM/LTO/V BY JMZWM F ATTORNEYS 1967 w. HAMILTONPROPORTIONING APPARATUS Filed July 7, 1965 s sheets-sheet 2 INVENTORWALLACE HAM/LTO/V ATTORNEYS.

Oct. 17, 1967 Filed July 7, 1965 W. HAMILTON PROPORTIONING APPARATUS 3Sheets-Sheet 5 INVENTOR WALLACE HAM/L 7'0/V ATTORNEYS United StatesPatent 3,347,416 PROPORTIONING APPARATUS Wallace Hamilton, ChagrinFalls, Ohio, assignor to Lewis Welding and Engineering Corporation, acorporation of Ohio Filed July 7, 1965, Ser. No. 470,002 8 Claims. (Cl.222-56) This invention, as indicated, relates to an apparatus forproportioning fluids, and more particularly to an apparatus for dilutingor mixing concentrated solutions to be predetermined concentration anddispensing the resultant solution.

Although the description of this invention is described in reference toproportioning and dispensing a solution composed of a singleconcentrated solution and a single diluting agent, it should beunderstood that the principles of this invention are applicable inproportioning and mix. ing together a number of concentrated solutions,or diluting a concentrated solution with different diluents, or acombination of both. For example, the apparatus of this invention mightbe used in continuously mixing and distributing solutions to baths inwhich photographic film is processed. This apparatus then, as indicated,is well suited for continuously proportioning, mixing and dispensingvarious solutions.

A most important utilization of this apparatus is in connection with anartificial kidney. Therefore, its description will be given in relationthereto.

It is well recognized that the kidneys are vital to the health of thebody, as they act as dialyzing membranes for removing contaminants inthe blood. Without such membranes, the contaminants would causepoisoning of the blood stream which inevitably brings death.

In recent years, an apparatus known as an artificial kidney forconditioning the blood has been developed and is used to bypassdefective kidneys permitting them to remain inactive for a period oftime sufiicient to permit their spontaneous return to normal capacity tofunction. This apparatus is also employed to remove contaminants andwastes from the blood of'people who have no kidneys. The treatment isadministered on an average of 1-3 times per week depending on theindividual. This treatment is extremely important, as the patient wouldsoon die if it was not avialable.

The artificial kidney is attached to the vascular system at twodifferent points of the body, normally the arms. Blood is pumped from anartery into the artificial kidney, dialyzed and then returned to thebody through a vein. The blood must be constantly circulated through theapparatus, i.e. similar to the normal circulation of the blood throughthe kidneys to reduce the accumulation of deleterious substances in theblood stream.

The blood is submitted to dialysis in conjunction with a dilutedsolution of one or more salts which is passed through the apparatus andseparated from the blood by a dialysis membrane. In one embodiment bloodfrom the patient is passed through an elongated, flattened thin walledspirally wound plastic tube which serves as the dialysis membraneimmersed in a circulating salt bath and returned to the patient. Theeifect of the salt solution and its concentration relative to the bloodand the permeability of the tube to the Waste materials permits aprocess known as dialysis to take place to remove waste material fromthe blood stream. The salt solution once it passes through the apparatusis ordinarily not recycled and reused. Therefore, it is readilyunderstood that there is a need for a constant supply of solution. Thesolution must be properly proportioned and diluted for conditioning theblood, and it must be also heated to keep the blood at body temperature.A suitable concentrated salt solution is readily avail- 3,347,41Patented Oct. 17, 1967 an apparatus. Costs are greatly reduced and moremachines can be made more widely available to the many people who aresulfering kidney disorders. The capacity of the device hereinafterdescribed is based on furnishing 300 cubic centimeters of solution perminute to each of five people. In other words, this metering apparatusprovides size of the various tanks as will become apparent from thefollowing description.

view of .an embodiment of this Referring generally to FIGS. 1-3, andmore particularly to FIGS. 1 and 2.0f the annexed drawings, there isshown a proportioning device or apparatus, generally indicated 0. Theapparatus 10 contains a plurality of tanks, e.g. a concentrate solutionstorage tank 12, a metering or measuring tank 14, for the concentratesolution, a separate metering or measuring tank 16 for the diluent orsolvent, a mixing tank 18 and a dispensing tank 26. As shown in thedrawing, the tanks 14 and 16 each have single compartments which arefixed in size.

In the illustrative embodiment, storage tank 12 contains in concentratedform a salt solution used in an artificial kidney (not shown) forremoving contaminents concentrated salt solution is forced, by anysuitable means, e.g. pump 32, into the metering tank 14, where it ismeasured for dilution with a proportionate amount of water, measured inthe tank 16. In the embodiment shown, the concentrated salt solution ispumped into tank 14, from an S-shaped siphon tube 22 having its tube end24 extending into the tank 12 and the salt solution therein. As the saltsolution will seek its own level in the siphon tube 22, the level of thesalt solution in the upstanding portion 26 of tube 22, acts as a scaleindicating the level of the concentrated salt solution in the storagetank 12.

The metering tank 14 (FIG. 2) has an inlet 34 and an overflow 44, whichfor convenience of manufacture are axially aligned. A piece of tubing orline 28 secured to the inlet 34 communicates with the siphon tube 22adjacent its upstanding portion 26. The pump 32 is interposed in theline 28, and serves to pump the concentrated salt solution from thesiphon tube 22 and storage tank 12, into the measuring tank 14. Tank 14is preferably vented, e.g. vent 29.

This invention contemplates variable means to be used to measure theamount of concentrated solution in variable volume tank 14. For example,the tank 14 (FIG. 2) has its open end 36 sealed by a top or ring 38having a centrally or eccentrically disposed opening 40 extendingtherethrough. A plunger 42 is inserted through the opening 40 into thetank 14. The volume of the diluent or water is preferably kept constantin the tank 16. Therefore, the concentration of the final solution iscontrolled by varying the volume of concentrated salt solution. This isaccomplished with the plunger 42. The further the plunger 42 is insertedinto the tank 14, Le. the greater its displacement, the less volume ofconcentrated solution will be used. A scale (not shown) indicating thenumber of parts of water per part of concentrated salt solution, e.g.the positions of plunger 42 shown in dotted lines and indicated forexample, proportions of 35:1 and 45:1, i.e. 35 or 45 parts of dilutesolution to one part of concentrated solution, may be placed on theplunger 42, or the tank 14, or cooperate with the plunger 42, whicheveris more convenient. The plunger 42 may be raised or lowered in the tank14 by any suitable means. A piece of tubing or line 46 (FIG. 1) issecured to and communicates with the overflow 44. The free end of theline 46 extends into the mouth 48 of the siphon tube 22. In this manner,the excess or displaced fluid is taken from the tank 14, and restored inthe tank 12 and siphon tube 22 for reuse.

A piece of plastic tubing or line 30, e.g. polyethylene tubing, issecured to, communicates with and extends from the lowest drainage pointof tank 14 into the mixing tank 18. A flow valve 50 disposed in the line30, regulates the flow of the metered solution from the tank 14 into thetank 18.

The filling of the measuring tank 16 is substantially simultaneous withthe filling of tank 14. A pipe or line 54 communicates between a sourceof water supply, e.g. a tap or faucet (not shown), and the measuringtank 16. A valve 56 is disposed in the line 54 to regulate the flow ofwater into the measuring tank 16. When the valve 56 is open, water isforced into the measuring tank 16 by any suitable means. In mostinstances, the line pressure is sufficient to cause'the water to flowinto the tank 16.

The top of the tank 16 is provided with a vent line 60 forming arestricted orifice where the line is joined to the top. As tank 16fills, air is vented through this orifice or opening. When water reachesthe orifice, the effect of the restriction on the flow causes anincrease in pressure within the water body which is utilized to actuatea pressure sensitive switch 58 which closes the valve 56 cutting off theflow of water into the tank 16. The pressure switch 58 is also utilizedto shut-oil? pump 32. The tank 14 has a smaller volume than tank 16 andis therefore filled before tank 16. The concentrate is continuouslypumped or circulated through tank 14 until the switch 58 is activated toshut off pump 32.

A pipe or line 62 is secured to, communicates with,

and extends from the lowest drainage point of the tank 16 into themixing tank 18. A valve 64 disposed in the line 62 regulates the flow ofwater between the measuring tank 16 and the mixing tank 18.

The mixing tank 18 is preferably disposed below the measuring tanks 14and 16, respectively. When the valves 50 and 64, respectively, areopened, the measured amounts of concentrated salt solution and water,respectively, flow from tanks 14 and 16 into the mixing tank 18. Thewater and the concentrated salt solution are thoroughly mixed in themixing tank 18 by any suitable means, e.g. a mixer or stirrer 66.

The solution in tank 18, is simultaneously heated by any suitable means,e.g. a thermostatically controlled heat coil 68. When used inconjunction with an artificial kidney, it is necessary to heat thediluted salt solution to temperatures ranging from about F. to about F.,so that when it passes through the artificial kidney, the blood will bemaintained near body temperature. Depending on the process for which theapparatus 10 is used, the mixed solution may be kept at room temperture,heated, or cooled.

In the illustrative embodiment, the dispensing tank or reservoir 20 isdisposed below the mixing tank 18. A piece of tubing or line 70 issecured to, communicates with, and extends from the lowest drainagepoint of the tank 18, into the dispensing tank 20. A valve 72 disposedin the line 70, regulates the flow of fluid between the tanks 18 and 20,respectively. A piece of tubing or line 74 is secured to, communicateswith, and extends from the lowest drainage point of the dispensing tank20. The line 74 extends from the proportioning apparatus 10 forattachment to the artificial kidney. A pump 76 disposed in the line 74regulates the flow of the diluted salt solution from the dispensing tank20 into the artificial kidney.

As previously indicated, the capacity of the unit is based on furnishing300 cc. per minute to each of 5 people. To accomplish this, the variablevolume tank 14 has a capacity of about 0.3 liter, the measuring tank 16a capacity of about 7.5 liters, the mixing tank 18 a capacity of about10 liters, and the dispensing tank 20 a capacity of about 11 liters.

Although the valves controlling the flow of fluid between the tanks maybe manually operated, it is desirable to have them responsive toelectrically activated devices to control their opening and closing.Programming devices also control the operation of pump 32. The operationof such devices will hereinafter be more fully described.

The embodiment of the proportioning apparatus 10, shown in FIG. 3, isessentially the same with a few improvements. A thermostaticallycontrolled heat coil 68a is disposed in the reservoir or dispensing tank20, and helps keep the mixed and diluted solution at a predetermineddesired temperature, e.g. about 102 F., the heat coil 68 in tank 18keeping the temperature of the solution at about 103 F., whereby thetemperature of the diluted solution is kept between about 100 F. and 105F. The heating of the diluted solution can be aided, for example, bypreheating the diluent. For example, when water is then diluent, bothhot and cold water from their respective faucets or taps could besupplied to the measuring tank 16.

The dispensing tank 20, for convenience, is disposed adjacent the mixingtank 18, and not below it. Therefore, a pump 82 must be disposed in theline 70 to pump the solution from tank 18 into tank 20.

From the aforementioned description of the parts of the apparatus 10,and their positions relative to each other, it is apparent that the rateof flow into tanks 18 and 20 must be greater than the rate of flow fromthe tank 20. Otherwise the tank 18 would be dry at times, and not ableto supply the solution to the tank 20. This problem is overcome in anumber of ways. For example, the pump 76 is made to pump at a slowerrate, or the tank 20 made larger to increase the amount of reservesolution, or pumps used to pump the solution from tanks 14 and 16,respectively, into tank 18. The actuating and programming devices may bemore fully understood by having reference to FIG. 4, which is aschematic drawing of a system employing a conventionally designed stepswitch 90 for controlling the operation of the valves and pumps in theproportioning apparatus of FIGS. 1 and 3. This system convenientlyoperates on 110 volts and comprises power leg L and neutral leg L Thestep switch 90 is disposed in the circuit for controlling the sequentialoperations of filling and emptying the various tanks. To begin operationof the apparatus 10, it is assumed that the various tanks are filled,the valves closed and the pumps shut off. A switch 88, controlling thenormal operation of the apparatus 10, is turned to its on positionclosing the electrical circuit. The pump 76 begins pumping solution fromthe reservoir or dispensing tank 20. At this point the step switch is inits first position or station S When the solution reaches apredetermined level within tank 20, the float 78 activates float switch80. An electrical impulse is sent from switch 80 through a steppingmechanism 79 moving the step switch 90 to its second position or stationS In this position, the circuits to valve 72 or pump 82, are closed andthe valve 72 opens or the pump 82 begins pumping the solution from tank18 into the reservoir 20. When the solution in tank 18 reaches apredetermined level, the float 78a activates float switch 80a. Anelectrical impulse is sent from switch 80:: through the steppingmechanism 79 moving step switch 90 to its third position or station S Inthis position the electrical circuits controlling the operation of valve72 or pump 82 are broken, and valve 72 closes or pump 82 shuts off. Alsovalves 50 and 64 are opened and a timing device 86 is activated. Thetiming device is set to permit tanks 14 and 16, respectively, to empty.After the allotted time has passed, an electrical impulse is sent fromtimer switch 83 through the stepping mechanism 79 moving step switch 90to its fourth position or station 8,.

In this position, the electrical circuits controlling the operation ofvalves 50 and 64, respectively, and timing device 86 are broken, and thevalves close and the timing device is shut olf. Simultaneously, pump 32and valve 56 are activated, and concentrate is pumped from the storagetank 12 into the measuring tank 14, and the diluent flows through valve56 into measuring tank 16, respectively. The pressure switch 58 isactivated when the tank 16 is filled with diluent. An electrical impulseis sent from switch 58 through the stepping mechanism 79 moving andreturning the step switch 90 to its first position 8,. In this position,the electrical circuit to the pump 32 and valve 56, respectively, isbroken and pump 32 shuts off and valve 56 closes. The cycle is repeatedwhen pump 76 pumps solution from the tank 20 down to the predeterminedlevel for activating float 78.

Although the proportioning apparatus 10, because of its simplicity, isrelatively free from malfunctions, it must, nevertheless, have a systemfor warning of any such malfunctions or breakdowns. Any suitable meansmay be used to accomplish this. For example, different colored lightsmight provide warnings that different tanks are not filling or emptyingproperly. This type of system would immediately pinpoint the troublearea, and instant action could be taken to correct the ditficulty. Sucha warning system is extremely important when the apparatus 10 is used inconjunction with the artificial kidney.

As previously indicated, when the apparatus 10 is used in conjunctionwith the artificial kidney, the temperature of the dispensed dilutedsolution must be from about 100 F. to about 105 F. A safety device (notshown) must be provided to insure that the temperature of the dispensedsolution is in the prescribed range. Any suitable means may be used toaccomplish this. For example,

a thermostatically controlled valve could be disposed in the line 74leading from the apparatus 10. If the solution were not within theprescribed range, the valve would operate to close line 74 leading tothe artificial kidney, and open a bypass conduit leading to a drain orother means for disposing the improperly heated solution. The valvewould only permit the passage of properly heated solution to theartificial kidney.

When used in conjunction with the artificial kidney, the apparatus 10must be periodically sterilized. This is accomplished by passing andholding liquids, e.g. water, heated to a temperature of about 200 F., inthe apparatus for a period of time, and then flushing it with cool orcold water.

Thus, there has been provided a new and novel apparatus for dilutingand/or mixing concentrated solutions. The parts of the proportioningapparatus may be made of any suitable materials depending on the type ofsolutions diluted and/or mixed. However, when used with the artificialkidney, it is mandatory that only certain materials be used, e.g.non-corrosive metals, glass and some clinically tested and approvedplastics. In this case, the apparatus performs a lifesaving function,and to eliminate any breakage or malfunctions of the parts, it ispreferable that they be made of stainless steel. The parts of thisapparatus are simply designed and economically manufactured. As seen inFIG. 1, the comparatively simple design of the metering apparatus makesit readily free from malfunctions which, as previosuly indicated, ismost important when used with the artificial kidney.

Other modes of applying the principle of this invention may be employedinstead of those specifically set forth above, changes being made asregards the details herein disclosed, provided the elements set forth inany of the following claims, or the equivalent of such, be employed.

It is, therefore, particularly pointed out and distinctly claimed as theinvention:

1. An apparatus for proportioning at least two liquids, comprising:

(a) a first tank having a single compartment whose volume is fixed andunadjustable for measuring a fixed amount of the first of said twoliquids;

(b) a storage tank for storing a second liquid;

(c) a second tank having a single fixed compartment for measuring aproportionate amount of the second of said two liquids;

(d) a plunger adjustable in the second tank for varying the amount ofliquid therein relative to the fixed amount of liquid in said firsttank;

(e) a third tank for receiving by gravity,

from said first and second tanks;

(f) means coacting with the first tank for regulating the flow of thefirst liquid into the first tank, the means responsive to the filling ofthe first tank and the emptying of the third tank;

(g) means coacting between the storage tank and the second tank forregulating the flow of the second liquid between the tanks, the meansresponsive to the filling of the first tank and emptying of the thirdtank;

(h) means disposed in the third tank for mixing the liquids together;

(i) means disposed in the third tank for regulating the temperature ofthe liquid in the third tank;

(j) means coacting between the first and second tanks, respectively, andthe third tank for regulating the flow of the liquids between the tanks,whereby the third tank is filled and the first and second tanks areemptied, the means responsive to the emptying of the first, second andthird tanks;

(k) a reservoir for receiving and storing the liquid from the third tankuntil it is dispensed;

(1) means coacting between the reservoir and third the liquid tank, forregulating the flow of the liquids therebetween, the means responsive tothe emptying of the reservoir and third tank; and

(m) means for regulating the flow of liquid from the reservoir.

2. The apparatus of claim 1, wherein the means for varying the volume ofthe second tank includes a plunger reciprocable in the second tank fordisplacing a volume of the second liquid and means for removing thedisplaced volume of the second liquid from the tank.

3. The apparatus of claim 2, wherein the volume of the reservoir isgreater than that of the third tank.

4. The apparatus of claim 3, wherein the means for regulating the flowof liquid from the third tank to the reservoir includes separate meansdisposed in the reservoir coacting with the liquid in the reservoir toactivate the flow means when the solution reaches a predetermined levelin the tank.

5. The apparatus of claim 4, wherein the means for regulating the flowof the first and second liquids into the third tank includes separatemeans disposed in the third tank coacting with the liquid in the thirdtank to activate the flow means when the liquid reaches a predeterminedlevel in the third tank.

6. An apparatus for proportioning at least two liquids, comprising incombination:

(a) a first tank having a single compartment whose volume is fixed andunadjustable for measuring a fixed amount of the first of said twoliquids;

(b) a second tank having a single fixed compartment 8 for measuring aproportionate amount of the second of said two liquids;

(c) a plunger adjustable in the second tank for varying the amount ofliquid therein relative to the fixed amount of liquid in said firsttank;

(d) a third tank for receiving by gravity, the liquid from said firstand second tanks, said liquids being mixed in said third tank to form asolution;

(e) means for dispensing at least a portion of the solution from saidthird tank; and

(f) means responsive to said dispensing means (e) for regulating thereceiving of liquids into said third tank.

7. The apparatus of claim 6, which includes:

(i) means disposed in the third tank for mixing the predeterminedvolumes of the liquids together.

8. The apparatus of claim 6, which includes:

(j) means disposed in the third tank for regulating the temperature ofthe liquid.

References (Iited UNITED STATES PATENTS 2,380,884 7/1945 Van Stoeser etal. 222-76 X 2,946,488 7/1960 Kraft 222134 3,145,881 8/1964 Moore et a1222--318 X 3,216,622 11/ 1965 Drostholm 222318 X ROBERT B. REEVES,Primary Examiner.

HADD S. LANE, Examiner.

6. AN APPARATUS FOR PROPORTIONING AT LEAST TWO LIQUIDS, COMPRISING INCOMBINATION: (A) A FIRST TANK HAVING A SINGLE COMPARTMENT WHOSE VOLUMEIS FIXED AND UNADJUSTABLE FOR MEASURING A FIXED AMOUNT OF THE FIRST OFSAID TWO LIQUID; (B) A SECOND TANK HAVING A SINGLE FIXED COMPARTMENT FORMEASURING A PROPORTIONATE AMOUNT OF THE SECOND OF SAID TWO LIQUIDS; (C)A PLUNGER ADJUSTABLE IN THE SECOND TANK FOR VARYIN THE AMOUNT OF LIQUIDTHEREIN RELATIVE TO THE FIXED AMOUNT OF LIQUID IN SAID FIRST TANK; (D) ATHIRD TANK FOR RECEIVING BY GRAVITY, THE LIQUID FROM SAID FIRST ANDSECOND TANKS, SAID LIQUIDS BEING MIXED IN SAID THIRD TANK TO FORM ASOLUITION; (E) MEANS FOR DISPENSING AT LEAST A PORTION OF THE SOLUTIONFROM SAID THIRD TANK; AND (F) MEANS RESPONSIVE TO SAID DISPENSING MEANS(E) FOR REGULATING THE RECEIVING OF LIQUIDS INTO SAID THIRD TANK.